<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html lang="en">
<head>
	<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
	<title>盒子</title>
</head>
<body>
	<div class="box" style="height:200px;width:200px;background:#333;"></div>
</body>
<script type="text/javascript">
	box = document.getElementsByClassName("box")
	// height = 
	
	// console.log(box[0].style.height)
	//return window.getComputedStyle ? window.getComputedStyle(obj,null).paddingLeft : obj.currentStyle.paddingLeft; 

	x=200
	box[0].onmouseover = function  () {
		box[0].style.height='px';
		box[0].style.width=x+=10 +"px";
	}
	x=400
	box[0].onmouseout = function  () {
		box[0].style.height=x-=10 +'px';
		box[0].style.width=x-=10 +'px';
	}



	//鼠标移动进去放大一倍，拿出来恢复原来
</script>
</html>